Multinode Hardware
Recommendations

When
configuring the multinode feature, consider the following:

Cisco recommends
turning on High Availability in your deployment.

Cisco only
supports virtualized deployments of
IM and Presence
Service on Cisco Unified Computing System servers or on a
Cisco-approved third-party server configuration. Cisco does not support
deployments of IM and Presence on Cisco Media Convergence Server (MCS) servers.
For more information about the deployment of
IM and Presence
Service in a virtualized environment, see
http://docwiki.cisco.com/wiki/Unified_Communications_in_a_Virtualized_Environment.

Minimize your
deployment, for example, instead of using five virtual machines that support a
total of two thousand users, choose two virtual machines that can support a
total of five thousand users.

Use the same
generation of server hardware.

Use similar
hardware for all nodes in your deployment. If you must mix generations of
similar hardware, put the same generations of older hardware together in a
presence redundancy group and put fewer users on this presence redundancy group
than on the more powerful presence redundancy group. Note that we do not
recommend this deployment practice.

Warning

For multinode
deployments, instead of using mixed virtual machine deployment sizes, it is
highly recommended that the
IM and Presence
Service subscriber and database publisher nodes in the same presence
redundancy group have similar database size. If a significant difference in
database size exists between the two nodes, you will receive an error during
installation of the subscriber node.

For a list
of the supported hardware for the multinode feature, and hardware user
assignment guidelines for the multinode feature, see the
IM and Presence Service compatibility matrices at this
URL:

Intercluster
Hardware Recommendations

When planning an intercluster
deployment, it is recommended that similar deployments be used on all
IM and Presence Service clusters in the Enterprise to
allow for syncing of all user data between clusters. For example, if a virtual
server supporting a 5000 user deployment is used in Cluster A, then a 5000 user
virtual server deployment should be used in Cluster B even if only 500 users
are needed in Cluster B .

Supported End
Points

The
multinode scalability feature supports the following end points:

Cisco Unified Communications
Manager (desk phone)

Cisco Jabber

Third-Party XMPP
clients

Cisco Unified
Mobile Communicator

Microsoft
Office Communicator (Microsoft soft client)

Lotus Sametime
(Lotus soft client)

Note

Lotus clients are used on the Microsoft server that is
integrated with
IM and Presence
Service for remote call control.

Third-Party
Interface clients

Lync 2010 and
2013 Clients (Microsoft Office Communicator)

Only third party clients support the Directory URI IM address scheme. All other clients
should use the
UserID@Default_Domain IM address
scheme. See topics related to the
IM and Presence Service IM address schemes for more
information.

WAN Bandwidth Requirements

At a minimum, you must dedicate 5 Mbps of bandwidth for each IM and Presence Service presence redundancy group, with no more than an 80 millisecond round-trip latency. These bandwidth recommendations apply
to both intracluster and intercluster WAN deployments. Any bandwidth less than this recommendation can adversely impact performance.

Note

Each IM and Presence Service presence redundancy group that you add to your Clustering over WAN deployment requires an additional (dedicated) 5 Mbps of
bandwidth.

WAN Bandwidth
Considerations

When you
calculate the bandwidth requirements for your Clustering over WAN deployment,
consider the following:

In your
bandwidth considerations, you must include the normal bandwidth consumption of
a
Cisco Unified Communications
Manager cluster. If you configure multiple nodes,
Cisco Unified Communications
Manager uses a round-robin mechanism to load balance SIP/SIMPLE
messages, which consumes more bandwidth. To improve performance and decrease
traffic, you could provision a single dedicated
Cisco Unified Communications
Manager node for all SIP/SIMPLE messages sent between the
IM and Presence
Service and
Cisco Unified Communications
Manager.

In your
bandwidth considerations, we also recommend that you consider the number of
contacts in the contact list for a
Cisco Jabber user, and the size of user profiles on
IM and Presence
Service. See the
IM and Presence
Service SRND for recommendations regarding the size of a contact list
when you deploy
IM and
Presence over WAN. Note also that the maximum contact list size on
IM and Presence
Service is 200, so you need to factor this in to your bandwidth
considerations for systems with large numbers of users.

For
additional information, see the
IM and Presence
Service Solution Reference Network Design (SRND):

Multinode Performance Recommendations

You can achieve optimum performance with the multinode feature when:

The resources on all IM and Presence Service nodes are equivalent in terms of memory, disk size, and age. Mixing virtual server hardware classes results in nodes that
are under-powered, therefore resulting in poor performance.

You deploy virtual server hardware that complies with the hardware recommendations.

You configure a Balanced Mode deployment model. In this case, the total number of users is equally divided across all nodes
in all presence redundancy groups. The IM and Presence Service defaults to Balanced Mode user assignment to achieve optimum performance.

User License
Requirements

IM and
Availability functionality does not require a node license or software version
license. However, you must assign IM and Availability functionality to each
IM and Presence Service
user.

You can
assign IM and Availability on a per user basis, regardless of the number of
clients you associate with each user. When you assign IM and Availability to a
user, this enables the user to send and receive IMs and also to send and
receive availability updates. If the user is not enabled for IM and
Availability, no availability updates are allowed for that user.

You can enable a
user for
IM and Presence Service
functionality in the
End User
Configuration window in Cisco Unified Communications Manager. See
the
Cisco Unified
Communications Manager Administration Guide for more information.

IM and
Availability functionality is included within both User Connect Licensing (UCL)
and Cisco Unified Workspace Licensing (CUWL). Refer to the
Cisco Unified
Communications Manager Enterprise License Manager User Guide for more
information.

DNS Domain and
Default Domain Requirements

The following DNS
domain and
IM and Presence Service default domain conditions
apply. To resolve any domain-related deployment issues, Cisco recommends that
you set all
IM and Presence Service node names in the cluster to
the FQDN or IP address rather than the hostname.

For
inter-cluster
IM and Presence
Service deployments, it is required that each
IM and Presence
Service cluster shares the same underlying DNS domain.

The DNS domain
associated with any client devices should map to the
IM and Presence
Service DNS domain.

Ensure that
the DNS domain aligns with the
IM and Presence
Service default domain.

The
IM and Presence
Service default domain value is set to the DNS domain by default
during installation. You can not change the
IM and Presence
Service default domain during installation. To change the default
domain to a value that is different from the DNS domain, you must use the Cisco
Unified CM IM and Presence Administration GUI.

Caution

Failure to set
all
IM and Presence
Service node names in the cluster to the FQDN or IP address rather
than the hostname can result in communications failure between nodes in a
cluster. Affected functions include SIP and XMPP-based inter-cluster
communications, High Availability, client sign-in, and SIP-based list
subscriptions.